Golf club head

ABSTRACT

An exemplary golf club head having additional discretionary mass may be realized by utilizing light-weight materials, an favorable average crown height, and/or articulation points. By using a preferred break length, the additional discretionary mass may be placed low and deep in the club head to improve the location of the center of gravity as well as the inertial properties. In one example, the center of gravity may be positioned to substantially align the sweet spot with the face center of the club head.

This is a Continuation-in-Part of application Ser. No. 11/717,107, filedMar. 13, 2007, which claims the benefit of U.S. Provisional ApplicationNo. 60/876,537 filed Dec. 22, 2006. The disclosures of the priorapplications are hereby incorporated by reference herein in theirentirety.

A Computer Program Listing Appendix on compact disk is included withthis application.

BACKGROUND

Wood-type golf club heads generally have a mass in the range of about150-250 g. A portion of this mass sustains the structural integrity ofthe club head. The remaining mass, referred to as “discretionary” mass,may be strategically distributed to improve the head's mass propertiesand/or inertial characteristics.

Known methods of increasing the available discretionary mass, e.g.reducing the thickness of the club head walls, produce minimum benefits.Accordingly, the capacity of modern wood-type club heads to deliverimproved performance is qualified, in part, by the amount ofdiscretionary mass attainable through conventional methods.

Generally, golfers have a natural tendency to strike the golf ball aboutthe face center of the club head. The face center, in most wood-typeclubs, is the point on the club face where maximum face rebound occursat ball impact and is also known as the Coefficient of Restitution (COR)“hot spot”. Although ball impact at the COR “hot spot” yields maximumface rebound, it may produce inaccurate shots because, in conventionalclub heads, the “sweet spot” (the orthogonal projection of the head'scenter of gravity (CG) onto the striking surface of the head and thepoint on the club face where no head rotation or gear effect occurs) isgenerally located above the COR “hot spot”. Hence, for conventionalwood-type clubs, only a single performance variable, i.e., eithermaximum face rebound associated with ball impact about the COR “hotspot” or shot accuracy associated with ball impact about the “sweetspot”, may be augmented for any one golf shot.

Generally, ball impact about the face center of a conventional wood-typeclub exaggerates both the head rotation and gear effect of the clubhead, causing a loss of carry distance and accuracy.

Shot accuracy and distance are also affected by the depth of the CGrelative to the club face. In conventional drivers, the CG is typicallypositioned near the face. Shallow CG placement decreases dynamic flexingof the shaft toward alignment with the CG, thus decreasing thebeneficial lofting of the head and the closing of the face at impactwith the ball. Additionally, a shallow CG decreases the radius ofrotation of the face on off-center hits, thus decreasing shot accuracy.

SUMMARY

A need exists for a golf club head having additional discretionary mass,an improved center of gravity location, increased dynamic loftattributes at ball impact, and reduced hook/slice tendencies.

In one example, a golf club head according to one or more aspects of thepresent invention may include a total mass between about 150 g and about250 g and at least one non-metallic portion comprising at least about 8%of the total mass. The club head may further comprise a break length,between about 96 mm and about 140 mm, measured at a vertical distancebetween about 5 mm and about 10 mm from a ground plane.

In another example, a golf club head according to one or more aspects ofthe present invention may include a primary heel-toe moment of inertiaof at least about 3500 g·cm² and a total mass between about 150 g andabout 250 g. The golf club head may further include a club headcomponent comprising a secondary heel-toe moment of inertia that isbetween about 85% and about 99% of the primary heel-toe moment ofinertia. A light-weight component, comprising between at least about 8%of the total mass, may be coupled to the club head component and maycomprise a connecting member.

In another example, a golf club head according to one or more aspects ofthe present invention may include a primary high-low moment of inertiaof at least about 2500 g·cm² and a total mass between about 150 g andabout 250 g. The golf club head may further include a club headcomponent comprising a secondary high-low moment of inertia that isbetween about 85% and about 99% of the primary high-low moment ofinertia. A light-weight component, comprising between at least about 8%of the total mass, may be coupled to the club head component and maycomprise a connecting member.

In another example, a golf club head according to one or more aspects ofthe present invention may include a total mass between about 150 g andabout 250 g and at least one non-metallic portion comprising at leastabout 8% of the total mass. The club head may further comprise aplurality of reference paths, at least one of the plurality of referencepaths comprising an average height between about 20 mm and about 45 mm.

In another example, a golf club head according to one or more aspects ofthe present invention may include a total mass between about 150 g andabout 250 g and at least one non-metallic portion comprising at leastabout 8% of the total mass. The club head may further comprise aplurality of reference paths, at least one of the plurality of referencepaths comprising at least two articulation points.

In another example, a golf club head according to one or more aspects ofthe present invention may include a face portion, a body portion, and aperipheral attachment zone between the face portion and the bodyportion. The peripheral attachment zone may comprise a perimetric lengthand at least two discrete welds comprising between about 1% and about40% of the perimetric length.

These and other features, aspects, and advantages of the golf club headaccording to the invention in its various aspects and demonstrated byone or more of the various examples will become apparent afterconsideration of the ensuing description, the accompanying drawings, andthe appended claims. The drawings described below are for illustrativepurposes only and are not intended to limit the scope of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary implementations will now be described with reference to theaccompanying drawings, wherein:

FIG. 1 is a top plan view of an exemplary golf club in accordance withone or more aspects of the present invention.

FIG. 1 a is a front elevational view of the golf club head of FIG. 1.

FIG. 1 b is a front perspective view of the golf club head of FIG. 1.

FIG. 1 c shows a template for locating the face center of a golf clubhead.

FIG. 2A is a front elevational view of the golf club head of FIG. 1,positioned on a moment of inertia measurement instrument for purposes ofmeasuring heel-toe MOI.

FIG. 2B is a front elevational view of the golf club head of FIG. 1,positioned on a moment of inertia measurement instrument for purposes ofmeasuring high-low MOI.

FIG. 2C is a perspective view of a jig plate.

FIG. 3 is a front elevational view of the golf club head of FIG. 1.

FIG. 3A is a top plan view of the golf club head of FIG. 1.

FIG. 3B is a heel side elevational view of the golf club head of FIG. 1.

FIG. 4 is a heel side elevational view of the golf club head of FIG. 1.

FIG. 4A is a heel side elevational view of the golf club head of FIG. 1.

FIG. 5 is a front elevational view of the golf club head of FIG. 1.

FIG. 6 is a front elevational view of the golf club head of FIG. 1.

FIG. 7 is a front elevational view of the golf club head of FIG. 1.

FIG. 8 is a top plan view of the golf club of FIG. 1.

FIG. 9 is a front elevational view of the golf club of FIG. 1.

FIG. 10 is a cross-sectional view of the golf club head of FIG. 1.

FIG. 10A is a cross-sectional view of the golf club in accordance withone or more aspects of the present invention superimposed over aconventional club head.

FIG. 11A is a top plan view of the golf the golf club head of FIG. 1.

FIG. 11B is a cross-sectional view of a golf club head in accordancewith one or more aspects of the present invention.

FIG. 11C is a rear perspective view of the golf club head of FIG. 11B.

FIGS. 12A-12F illustrate a plurality non-arcuate junctions in accordancewith one or more aspects of the present invention.

FIG. 13A is a cross-sectional view of the golf club head of FIG. 1B.

FIG. 13B is a cross-sectional view of a golf club head according to oneor more aspects of the present invention.

FIG. 13C illustrates an example of a non-arcuate junction.

FIG. 13D is a cross-sectional view of the golf club head of FIG. 13B

FIG. 14 is an exploded view of a golf club head according to one or moreaspects of the present invention.

FIG. 15 is an exploded view of a face portion of FIG. 14

FIG. 16A is a toe-side elevational view of the golf club head of FIG.14.

FIG. 16B is a heel-side elevational view of the golf club head of FIG.14.

FIG. 17 is an exploded view of the golf club head of FIG. 14.

FIG. 18A is a partially exploded view of the golf club head of FIG. 14.

FIG. 18B is a partially exploded view of the golf club head of FIG. 14.

FIG. 19A is an exploded view of a golf club head according to one ormore aspects of the present invention.

FIG. 19B is a top plan view of the golf club head of FIG. 19A.

FIG. 19C is a bottom plan view of the golf club head of FIG. 19A.

FIG. 19D is a top plan view of a golf club head in accordance with oneor more embodiments of the present invention.

FIG. 19E is a bottom plan view of the golf club head of FIG. 19D.

FIG. 20 is an illustration of the light-weight component according toone or more aspects of the present invention.

FIG. 21 is a perspective of club head component according to one or moreaspects of the present invention.

FIG. 22A is a top plan view of the club head component of FIG. 21.

FIG. 22B is a heel side elevational view of the club head component ofFIG. 21.

In the figures, like elements are designated by like reference numerals.

DETAILED DESCRIPTION

The following examples of the golf club head according to one or moreaspects of the invention will be described using one or moredefinitions, provided below.

Referring to FIGS. 1 and 1A, a club head 101 may comprise a toe 103, aheel 105, a hosel 100 having a central axis (centerline) 102, a soleportion 109 and a face portion 106. The face portion 106 includes astriking surface 111, a top edge 107, and a face center 112.

“Face center”, e.g., the face center 112, as used herein, may be locatedusing the general methodology described in the Procedure for Measuringthe Flexibility of a Golf Club head, Revision 2.0, Section 6.1 (Mar. 25,2005), as administered by the United states Golf Association (USGA) andR&A Rules Limited (R&A). Steps 6.1 through 6.1.4 of the Procedure forMeasuring the Flexibility of a Golf Club Head are herein incorporated byreference in their entirety. As shown in FIG. 1 c, the face center 112may be located using a template 113, having a coordinate system with aheel-toe axis orthogonal to a sole-crown axis. An aperture 119 may belocated at the origin of the coordinate system and each axis may bedivided into evenly spaced increments. The template 113 may be composedof a flexible material, e.g., a transparent polymer. The template isused as follows:

-   -   1) The template 113 is placed on the striking surface 111 with        the heel-toe axis substantially parallel to the leading edge        107. The template is then moved back and forth in the heel-toe        direction along the striking surface 111 until the heel and toe        measurements at the opposite edges of the striking surface 111        are equal.    -   2) The template 113 is moved back and forth in the sole-crown        direction along the striking surface 111 until the sole and        crown measurements at the opposite edges of the striking surface        111 are equal.    -   3) The template 113 is moved with respect to the striking        surface 111 as described in steps 1 and 2, above, until the heel        and toe as well as the sole and crown measurements along the        corresponding axes are equal. A circle is then marked on the        face via the aperture 119 to indicate the face center 112.

Referring again to FIGS. 1 and 1A, “reference position,” as used herein,denotes a position of the club head 101 where the hosel centerline 102is in an imaginary vertical plane 104 and is oriented at a lie angle αof substantially 60° with respect to a ground plane 108. The imaginaryvertical plane 104 is oriented substantially parallel to the top edge107 of the face 106.

Referring to FIG. 1B, for purposes of determining moments of inertia ofa golf club head according to one or more aspects of the invention, athree-dimensional coordinate system, having axes x, y, and z, has itsorigin at the center of gravity CG of the club head 101, with the clubhead in the reference position. The z-axis extends through the center ofgravity CG generally parallel to the striking surface 111 in a verticaldirection relative to the ground plane 108. The y-axis extends throughthe center of gravity CG substantially parallel to the striking surface111 and perpendicular to the z-axis. The x-axis extends through thecenter of gravity CG and is perpendicular to the z-axis and the y-axis.

The moment of inertia I_(zz) about the z-axis and the moment of inertiaI_(yy) about the y-axis (I_(yy)) of the club head 101 (i.e., the primaryheel-toe MOI and the primary high-low MOI) may be found using thegeneral methodology disclosed in the Procedure for Measuring the Momentof Inertia of Golf Clubheads, Revision 1.0 (Apr. 12, 2006), asadministered by the United States Golf Association (USGA) and R&A RulesLimited (R&A), with procedural modifications for measuring I_(yy)discussed below. The USGA Procedure for Measuring the Moment of Inertiaof Golf Clubheads is herein incorporated by reference in its entirety.The associated “USGA MOI Calculation.xls” program, in an executable formincluding its listing, is in the attached Computer Program ListingAppendix on compact disk.

As described in the USGA Procedure for Measuring the Moment of Inertiaof Golf Clubheads, a measuring instrument 117 (see FIGS. 2A and 2B),designed for determining the moment of inertia of test parts having massproperties and overall dimensions similar to that of a golf club head,may be used to obtain the moment of inertia I_(zz) (the primary heel-toeMOI) about the z-axis and the moment of inertia I_(yy) (the primaryhigh-low MOI) about the y-axis of the golf club head 101. Referring onceagain to FIGS. 2A and 2B, a horizontal jig plate 120, described in theUSGA Procedure for Measuring the Moment of Inertia of Golf Clubheads, isattached to the measuring instrument 117, such that the jig plate andthe measurement instrument are level.

As shown in FIG. 2C, the jig plate 120 has a first side 121 and a secondside 123. The first side 121 includes mounting pins 125 and the secondside 123 includes mounting pins 127. Pins 125 and 127 comprise rowsarranged longitudinally with respect to the jig plate and columnsarranged transversely with respect to the jig plate.

For purposes of measuring the primary heel-toe MOI of the club head 101about the z-axis, an adapter 118 a (FIG. 2A) is utilized to orient theclub head with respect to the jig plate 120 so that the sole portion 109of the club head is facing up and the club head 101 is disposed suchthat the angle θ between the hosel centerline 102 and an imaginaryhorizontal plane 113 is substantially 60°. Furthermore, the face portion106 of the club head is substantially parallel to the rows of mountingpins 125 and 127. For purposes of measuring the primary heel-toe MOI ofthe club head 101, the pins 125 on the first side 121 of the jig plate120 are used for right-handed club heads and the pins 127 on the secondside 123 of the jig plate 120 are used for left-handed club heads.

For purposes of measuring the primary high-low MOI of the club head 101about the y-axis, an adapter 118 b (FIG. 2B) is utilized to orient theclub head with respect to the jig plate 120 so that the sole portion 109of the club head is substantially vertical. In other words, the clubhead 101 is disposed with respect to the jig plate 120 such that theangle β between the hosel centerline 102 and an imaginary vertical plane114, generally parallel to the sole portion 109, is substantially 60°.

Furthermore, as provided in the USGA Procedure for Measuring the Momentof Inertia of Golf Clubheads, the face portion 106 of the club head issubstantially parallel to the rows of mounting pins 125 and 127. Forpurposes of measuring the primary high-low MOI of the club head 101, thepins 125 on the first side 121 of the jig plate 120 are used forleft-handed club heads and the pins 127 on the second side 123 of thejig plate 120 are used for right-handed club heads.

Referring to FIG. 3, “hosel center”, e.g., the hosel center 122, as usedherein, refers to the point of intersection between the hosel centerline102 and an imaginary planar surface 129, characterizing the terminus ofthe hosel 100.

The location of the center of gravity CG of the club head 101 in thereference position may be described as follows:

-   -   (1) Referring to FIG. 3A, the center of gravity CG is disposed a        first horizontal distance 124 from an imaginary vertical plane        126. The plane 126 is oriented substantially parallel to the        striking surface 111 and contains the hosel center 122. The        distance 124 is the shortest horizontal distance from plane 126        to the center of gravity CG.    -   (2) Referring to FIG. 3A, the center of gravity CG is located a        second horizontal distance 128 from an imaginary vertical plane        130. The plane 130 is oriented substantially perpendicular to        the striking surface 111 and contains the hosel center 122. The        distance 128 is the shortest horizontal distance from the plane        130 to the center of gravity CG.    -   (3) Referring to FIG. 3B, the center of gravity CG is located a        vertical distance 132 from the ground plane 108. The distance        132 is the vertical distance from the ground plane 108 to the        center of gravity CG.

Referring to FIG. 4, “sweet spot”, e.g., the sweet spot 134, as usedherein, refers to the point of intersection between the striking surface111 and an imaginary line 136 that is substantially perpendicular to thestriking surface 111 and passes through the center of gravity CG of theclub head 101.

Referring to FIG. 5, “face height”, e.g., the face height 154, as usedherein, denotes a vertical distance between a first horizontal plane 156passing through the highest point 160 of the striking surface 111, andthe ground plane 108, with the club head in the reference position 101.

Referring to FIG. 6, “face length”, e.g., the face length 164, as usedherein, refers to a shortest horizontal distance between points 166 and168, with the club head 101 in the reference position. The point 166 and168 are characterized by the intersection of an imaginary horizontalplane 170, passing through the face center 112, with the peripheral edgeof the striking surface 111 adjacent the heel 105 and the toe 103,respectively, of the club head 101.

Referring to FIG. 7, “center apex”, e.g., the center apex 138, as usedherein, refers to a point of intersection between an imaginary verticalplane 140 and the top of the striking surface 111, with the club head101 in the reference position. The plane 140 is oriented substantiallyperpendicular to the striking surface 111 and passes through the facecenter 112.

Referring to FIG. 8, “overall length”, e.g., the overall length 182, asused herein, denotes the shortest horizontal distance between a firstimaginary vertical plane 185, substantially parallel to the strikingsurface 111 and passing through the center apex 138, and a secondimaginary vertical plane 186, that is parallel to the plane 185 andpasses through the furthest rearwardly projecting point 151 of the clubhead 101 in the reference position, opposite the striking surface 111.

Referring to FIG. 9, “overall width”, e.g., the overall width 190, asused herein, denotes the shortest horizontal distance between a firstimaginary vertical plane 192, substantially perpendicular to thestriking surface 111 and passing through the furthest laterallyprojecting point 196 of the toe 184, and a second imaginary verticalplane 194 that is substantially perpendicular to the striking surface111 and passes through the furthest laterally projecting point 198 ofthe heel 176 at a height of ¾″, with the club head 101 in the referenceposition.

Referring to FIG. 10, “break length”, e.g., the break length 142, asused herein, denotes a horizontal distance, at a vertical distance 144relative to the ground plane 108, in a direction substantiallyperpendicular to the striking surface 111, between an imaginary verticalline 146 and the outer surface of a rear portion 148 of the club head101, with the club head in the reference position. The imaginaryvertical line 146 extends from the center apex 138 to the ground plane108.

Referring to FIG. 19B, the term “top portion”, e.g., the top portion2050, as used herein, denotes the portion of the club head, excludingthe striking surface 111, visible in a top plan view with the club head2000 in the reference position.

Referring to FIG. 19C, the term “bottom portion”, e.g., the bottomportion 2060, as used herein, denotes the portion of the club headvisible in a bottom plan view with the club head 2000 in the referenceposition.

Referring to FIGS. 11A-11C, “average height”, as used herein, denotes anaverage of a plurality of vertical distances, F₁ . . . F_(n), betweenone or more of a plurality of reference paths P₁ . . . P_(n) (FIG. 11C)and the ground plane 108, with the club head 101 in the referenceposition. For example, as shown in FIG. 11B, reference path P₁ ischaracterized by the intersection of an imaginary vertical plane 140 anda top portion 2050 of an exemplary club head 101. The imaginary verticalplane 140 is oriented substantially perpendicular to the strikingsurface 111 and passes through the face center 112. Referring to FIG.11A, the reference path P₁ is bounded by the center apex 138 and theintersection of the vertical plane 140 with a peripheral edge 145. Theperipheral edge 145 comprises the perimetric boundary of the club headin a top plan view.

As shown in FIG. 11C, other reference paths, e.g., paths P₂, P₃, P₄, andP₅, may be laterally spaced from the reference path P₁, e.g., inincrements of one centimeter. Such reference paths are characterized byintersections of imaginary vertical planes (not shown), parallel to thereference path P₁, with the top portion 2050 of the club head 101 andare bounded by the top edge 107 and the peripheral edge 145. Verticaldistances F₁ . . . F_(n) are measured along any one of the plurality ofreference paths P₁ . . . P_(n) in evenly spaced horizontal incrementsof, e.g., one centimeter, originating at the top edge 107 andterminating at a location along the path nearest the peripheral edge145.

The term “non-arcuate junction,” as used herein, refers to a junction oftwo lines where an arcuate line intersects a straight line (FIGS. 12Aand 12B), an arcuate line intersects another arcuate line (FIGS. 12C,12D, and 12E), or a straight line intersects another straight line (FIG.12F).

Referring to FIG. 13A, “articulation point”, e.g., the articulationpoint 172, as used herein, denotes at least one point along one or moreof the plurality of reference paths P₁ . . . P_(n), described above withreference to FIG. 11C, where the curvature changes from concave toconvex or vice versa. When determining whether one of a plurality ofreference paths P₁ . . . P_(n) changes curvature, it is assumed that allnon-arcuate junctions along each reference path are arcuate. Forexample, each non-arcuate junction 178 of club head 153, illustrated inFIG. 13B, is substituted with an imaginary junction 180, having aninfinitesimally small radius, as shown in FIGS. 13C and 13D.

The term “discretionary mass”, as used herein, denotes the differencebetween a target mass of the club head and a minimum structural massrequired to form the club head.

The term “volume”, as used herein, denotes the volume determined usingthe method described in the Procedure for Measuring the Club Head Sizeof Wood Clubs, Revision 1.0, Section 5 (Nov. 21, 2003), as administeredby the United States Golf Association (USGA) and the R&A Rules Limited(R&A). As described in the Procedure for Measuring the Club Head Size ofWood Clubs, the “volume” is determined by using the followingmethodology:

-   -   1) Water is placed in a container large enough to completely        immerse a club head without the club head touching the        container;    -   2) The filled container is placed on a digital electronic scale        that is then tared;    -   3) The club head is slowly lowered into the container until the        top of the club head is just below the surface of the water. The        hosel of the club head should not be submerged.    -   4) The reading on the electronic scale with the club head        submerged as described in step 3, above, is equal to the actual        volume of the club head in cubic centimeters.

With reference to FIGS. 14 and 15, a wood-type club head according toone or more aspects of the invention may have a face portion 106 and abody portion 1000. The body portion 1000 may incorporate three separateelements, which may include a upper cover 1030, an intermediate portion1020, and a lower cover 1040. The upper cover 1030 and/or the lowercover 1040 may comprise a non-metallic material, such as a thermoset, athermoplastic, or a composite material. To increase the availablediscretionary mass, the non-metallic portions of the club headpreferably comprise at least about 30% of the head's total materialvolume, more preferably at least about 20% of the head's total mass, andmost preferably at least about 8% of the head's total mass. Generally,the total mass of a wood-type club head according to one or more aspectsof the present invention is between about 150 g and about 250 g. Theincreased discretionary mass may be redistributed in the club head toimprove the inertial properties of the club head and/or the location ofthe center of gravity.

The intermediate portion 1020 may comprise a metallic material toimprove the structural integrity and/or the inertial properties of theclub head. As shown in FIGS. 16A and 16B, the intermediate portion 1020may separate the upper cover 1030 from the lower cover 1040. Thecomponents of the body portion 1000 may be joined by any suitable means,e.g., an adhesive bonding material.

The club head in accordance with one or more aspects of the presentinvention utilizes a favorable average height, determined as definedabove. More specifically, decreasing the average height relative to thatof a conventional driver may require less material to form, e.g., theupper cover portion 1030, thus increasing available discretionary mass.The average height between at least one of the plurality of referencepaths P₁ . . . P_(n) (FIG. 11C) and the ground plane 108 may be, e.g.,between about 20 mm and about 45 mm, between about 35 mm and about 45mm, between about 36 mm and about 41 mm, between about 37 mm and about40 mm, between about 15 mm and about 30 mm, or between about 15 mm andabout 40 mm. The increased discretionary mass created by utilizing theexemplary average heights, recited above, may be redistributed in theclub head according to one or more aspects of the invention to improvethe mass properties thereof.

Moreover, an increase in available discretionary mass may be achieved byproviding at least one articulation point 172 (FIG. 13A) along one ormore of the plurality of reference paths P₁ . . . P_(n) on the topportion 2050 of the club head (FIG. 11C). By utilizing a favorablenumber of articulation points 172, a crown shape conducive to abeneficial weight distribution may be achieved. For example, asillustrated in FIG. 13A, a concavity 1015 may be formed in the topportion 2050 of the club head 101 by providing, e.g., two articulationpoints 172. Such club head construction allows the mass to beredistributed from the top portion of the club head to a more favorablelocation in the head. Accordingly, mass may be redistributed, e.g., toimprove the inertial properties of the club head and/or the location ofthe center of gravity CG. This may allow for a more forgiving club headand result in improved shot accuracy and distance.

According to one or more aspects of the present invention, the center ofgravity of the club head may be more favorably positioned as theadditional discretionary mass, obtained, e.g., by utilizing localizednon-metallic components, a favorable average height, and/or one or morearticulation points, is placed as low and deep as possible in theexemplary club head 101. The additional discretionary mass obtained asdisclosed above may take the form of one or more weight elements or padsthat may have a combined weight between, e.g., about 5 g and about 80 g.

As shown in FIG. 10A, conventional club heads, e.g., a club head 143,have limited potential to carry discretionary mass low and deep in thechassis, partially because their soles, e.g., sole 141, are generallyelevated with respect to the ground plane 108. Referring once again toFIG. 10A, a golf club head 101, according to one or more aspects of theinvention, comprises a sole 139, configured with the break length 142,which is elongated compared to a corresponding break length 142 a of theconventional club head 143, having a similar volume. The novelconfiguration of the sole 139, as evidenced by the increased breaklength 142, permits lower and deeper placement of discretionary mass inthe inventive club head 101, in its various exemplars, compared toconventional club heads, e.g., club head 143.

Accordingly, the club head 101 may have a break length 142 between about50 mm and about 110 mm at the vertical distance 144 between about 1 mmand about 15 mm relative to the ground plane 108. Preferably, the breaklength 142 may be between about 90 mm and about 150 mm, more preferablybetween about 96 mm and about 140 mm, even more preferably between about100 mm and about 140 mm, even more preferably between about 110 mm andabout 140 mm, and most preferably between about 120 mm and about 140 mm.at the vertical distance 144 between about 5 mm and about 10 mm relativeto the ground plane 108. The break length 142, in accordance with theone or more aspects of the present invention, allows discretionary massto be placed low and deep within the club head 143, delivering animproved location of the center of gravity.

As shown in FIG. 4A, the increased break length, associated withconfiguring the sole 139 according to one or more aspects of the presentinvention, may allow discretionary mass to be positioned sufficientlylow in the club head 101 to substantially align the sweet spot 134 withthe COR “hot spot”, i.e., the face center 112. By lowering the center ofgravity CG and aligning the sweet spot 134 with the COR “hot spot” 112,the benefits of two performance variables, i.e., the increased shotdistance associated with the COR “hot spot” 112 and the increasedaccuracy associated with the “sweet spot” 134, may be realizedsimultaneously.

The increased break length associated with configuring the sole 139 inaccordance with one or more aspects of the invention may also allow thecenter of gravity to be positioned deeper in the club head. Referring toFIG. 3A, the depth of the center of gravity is the shortest horizontaldistance, e.g., the distance 124, between the center of gravity CG andthe vertical plane 126, containing the hosel center 122. Increasing thedepth of the center of gravity CG enhances dynamic flexing of the shafttoward alignment with the center of gravity to loft the head and toclose the face preferably “square” at impact with the ball. Hence,ball-launch conditions and shot accuracy may be improved.

As shown in FIGS. 3A and 3B, the location of the center of gravity CG ofthe club head 101 may be further described with reference to the secondhorizontal distance 128 and the first vertical distance 132, as definedabove. In one or more aspects of the present invention, the firsthorizontal distance 124 may preferably be between about 12 mm and about38 mm, more preferably between about 15 mm and about 36 mm, and mostpreferably between about 25 mm and about 35 mm. The second horizontaldistance 128 may preferably be between about 40 mm and about 78 mm, morepreferably between about 50 mm and about 70 mm, and most preferablybetween about 55 mm and about 66 mm. The first vertical distance 132 maypreferably be between about 10 mm and about 30 mm, more preferablybetween about 10 mm and about 25 mm, more preferably between about 10 mmand about 20 mm, and most preferably between about 10 mm and about 15mm.

In addition to improving the location of the center of gravity,favorable placement of discretionary mass throughout the club head mayincrease the primary heel-toe MOI and the primary high-low MOI and mayultimately improve performance on off-center hits by reducing slice/hooktendencies. In accordance with one or more aspects of the presentinvention, the primary high-low MOI may preferably be at least about2500 g·cm² and more preferably at least about 3000 g·cm². The primaryheel-toe MOI may preferably be at least about 3500 g·cm², morepreferably at least about 4000 g·cm², and most preferably at least about4500 g·cm².

Referring to FIGS. 5 and 6, a quantity of available discretionary massmay also be utilized in the face portion 106 to make the strikingsurface 111 taller and wider. The large striking surface provides thegolfer with increased confidence, resulting in elevated club head speedsand increased ball carry distances. In accordance with one or moreaspects of the present invention, the face height 154 may preferably bebetween about 35 mm and about 70 mm, more preferably between about 45 mmand about 58 mm, and most preferably between about 48 mm and about 56mm. The face length 164 may preferably be between about 94 mm and about115 mm, more preferably between about 96 mm and about 112 mm, and mostpreferably between about 98 mm and about 110 mm.

The face portion 106, illustrated in FIGS. 14 and 15, may comprise a cupportion 1050 or a strike plate 1060 and an annular portion 1075,attached to the body portion 1000, for example, by welding, adhesivebonding, brazing, or other suitable means. Typically, face portion 106and the intermediate portion 1020 are composed of the same material;however, dissimilar materials may be utilized. For example, theintermediate portion 1020 may comprise a first metallic material, thestrike plate 1060 may comprise a second metallic material, and theannular portion 1075 may comprise a third metallic material. In someexamples, the density of the third metallic material may be greater thanthe density of the second metallic material and the density of thesecond metallic material may be greater than the density of the firstmetallic material. Various combinations of materials may result in aclub head having improved performance, cost, and/or aesthetic appeal.

As shown in FIGS. 16A and 16B, the face portion 106, according to one ormore aspects of the invention, may be coupled to the intermediateportion 1020 by two discrete welds, i.e., a first weld 1080, locatedabout the toe 103 of the club head 101, and a second weld 1090, locatedabout the heel 105. As illustrated in FIG. 17, each weld may lie in aperipheral attachment zone 1025, characterized by the junction betweenthe face portion 106 and the body portion 1000. The attachment zone 1025may be substantially planar or non-planar, i.e., substantiallytwo-dimensional or three-dimensional. The length of the welds 1080 and1090 in the peripheral attachment zone 1025 may be minimized to reducenegative effects, e.g., distortion, associated with high-temperaturejoining operations, such as welding. Preferably, welds 1080 and 1090comprise between about 1% and about 40% of the perimetric length of theperipheral attachment zone 1025. More preferably, welds 1080 and 1090comprise between about 1% and about 30% of the perimetric length of theperipheral attachment zone 1025. Even more preferably, welds 1080 and1090 comprise between about 1% and about 20% of the perimetric length ofthe peripheral attachment zone 1025. Most Preferably, the welds 1080 and1090 comprise between about 1% and about 10% of the perimetric length ofthe peripheral attachment zone 1025.

Each weld in the peripheral attachment zone 1025 may comprise one of anumber of various welding-joint configurations, including, e.g., a buttjoint, a lap joint, or a corner joint. Prior to welding each joint, tackwelds or clamping fixtures may be used to hold the parts to be joined inproper alignment.

Referring to FIGS. 18A and 18B, the remaining components of the bodyportion, i.e., the upper cover 1030 and the lower cover 1040, may bejoined to the assembly comprising the intermediate portion 1020 and theface portion 106 via, e.g., an adhesive bonding material. Support ledges1045 a and 1045 b may be provided in the intermediate portion 1020 andthe face portion 106 for attaching the upper cover 1030 and the lowercover 1040 thereto. Recessing support ledges 1045 a and 1045 b allowsthe upper cover 1030 and/or the lower cover 1040 to be disposedsubstantially flush with the rest of the club head. The finished clubhead may have both the overall length 182 (FIG. 8) and the overall width190 (FIG. 9) greater than about 75 mm. The volume of the club headaccording to one or more aspects of the invention may be less than about480 cm³, preferably less than about 400 cm³, more preferably less thanabout 390 cm³, and most preferably less than about 380 cm³.

Referring to FIGS. 19A-19E, a golf club head 2000, according to one ormore aspects of the invention, may include the face portion 106 and abody portion 1000 a. To increase the discretionary mass of the head, thebody portion 100 a may include a light-weight component 2100, having anupper element 2030, a lower element 2040, and, optionally, at least oneconnecting member, e.g., the connecting member 2070, extending betweenthe upper element 2030 and the lower element 2040. In another example,the light-weight component 2100 may comprise only the upper element 2030and at least one connecting member, e.g., the connecting member 2070,extending between the upper element 2030 and the bottom portion 2060(FIG. 19E) of the club head. In yet another example, the light-weightcomponent 2100 may comprise only the lower element 2040 and at least oneconnecting member, e.g., the connecting member 2070, extending betweenthe lower element 2040 and the top portion 2050 (FIG. 19D) of the clubhead. The light-weight component 2100 may comprise metallic materials,e.g., titanium, magnesium, aluminum and/or stainless steel, and/ornon-metallic materials, e.g., thermoplastics, thermosets, and/orcomposites.

Referring to FIG. 19A, the body portion 1000 a also includes a supportshell 2010 that may be coupled to the light-weight component 2100 by anysuitable means, e.g., adhesive bonding, welding, or brazing. As shown inFIGS. 19B and 19C, the light-weight component 2100 may be, at least inpart, bounded by the support shell 2010. To improve the inertialproperties of the club head 2000, the exemplary support shell 2010 maybe constructed from a material having a greater density than that of thelight-weight component 2100. Such construction may improve shot accuracyand carry distance on off-center hits. The support shell 2010 maycomprise metallic and/or non-metallic materials.

With reference to FIG. 20, the light-weight component 2100 may includeat least one connecting member, e.g., the connecting members 2070, toimprove the structural integrity and/or acoustic properties of the clubhead 2000. In one example, connecting members 2070 may extend from thelower element 2040 to the upper element 2030. The connecting members2070 may be substantially parallel or oblique relative to one another.Such construction of the light-weight component 2100 may improve theacoustic properties of the club head at impact with the ball bypromoting favorable vibrational frequencies.

The sound produced by a golf club head at ball impact may have asignificant psychological effect on the player's confidence andperformance. By incorporating the connecting members 2070 into the clubhead, a favorable dominant resonant frequency of vibration may beachieved. The dominant resonant frequency of vibration is defined as theresonant frequency that produces the greatest sound energy. To measurethe sound energy of a given resonant frequency, a time-amplitude plot,with the amplitude along the y-axis and the time along the x-axis, maybe generated. The resonant frequency having the greatest area underneaththe curve is the dominant resonant frequency of vibration. Generally,the first resonant frequency of vibration is the dominant resonantfrequency. Preferably, the first resonant frequency of vibration isbetween about 2000 Hz and about 7500 Hz, more preferably between about2500 Hz and about 6000 Hz, and most preferably between about 3000 Hz andabout 5000 Hz. In some instances, the dominant resonant frequency may bethe second, the third, the fourth, or the fifth resonant frequency ofvibration.

The total mass of the club head 2000 may be between about 150 g andabout 250 g. Preferably, the light-weight component 2100 comprises atleast about 20% of the total mass of the club head 2000, more preferablyat least about 30% of the total mass of the club head 2000, and mostpreferably at least about 40% of the total mass of the club head 2000.

Referring to FIG. 21, a golf club head in accordance with one or moreaspects of the present invention, may include a club head component 2200having the face portion 106 and a support shell 2010 a. The supportshell 2010 a may comprise at least one of a top opening 2210 and abottom opening 2220. In one example, the light-weight component (FIG.20), in its various configurations, may be coupled to the support shell2010 a.

For purposes of determining the moment of inertia I_(zz) about thez-axis and the moment of inertia I_(yy) about the y-axis (i.e., thesecondary heel-toe MOI and the secondary high-low MOI, respectively) ofthe club head component 2200, the general methodology discussed abovemay be used. Preferably, the secondary heel-toe and high-low moments ofinertia of the club head component 2200 are between about 85% and about99% of the corresponding primary moments of inertia of the entire clubhead, more preferably between about 88% and about 97% of thecorresponding primary moments of inertia of the entire club head, andmost preferably between about 90% and about 95% of the primarycorresponding moments of inertia of the entire club head.

As shown in FIGS. 22A and 22B, the location of the center of gravity CG′of the club head component 2200 may be described as follows:

-   -   (1) Referring to FIG. 22A, the center of gravity CG′ is disposed        a first horizontal distance 124′ from an imaginary vertical        plane 126′. The plane 126′ is oriented substantially parallel to        the striking surface 111 and contains the hosel center 122. The        distance 124′ is the shortest horizontal distance from plane        126′ to the center of gravity CG′.    -   (2) Referring to FIG. 22A, the center of gravity CG′ is located        a second horizontal distance 128′ from an imaginary vertical        plane 130′. The plane 130′ is oriented substantially        perpendicular to the striking surface 111 and contains the hosel        center 122. The distance 128′ is the shortest horizontal        distance from the plane 130′ to the center of gravity CG′.    -   (3) Referring to FIG. 22B, the center of gravity CG′ is located        a vertical distance 132′ from the ground plane 108. The distance        132′ is the shortest vertical distance from the ground plane 108        to the center of gravity CG′.

Referring once again to FIGS. 22A and 22B, the first horizontal distance124′, the second horizontal distance 128′, and the first verticaldistance 132′ may be between about 85% and about 99% of the firsthorizontal distance 124 (FIG. 3A), the second horizontal distance 128(FIG. 3A), and the first vertical distance 132 (FIG. 3B), respectively.More preferably, the first horizontal distance 124′, the secondhorizontal distance 128′, and the first vertical distance 132′ may bebetween about 88% and about 97% of the first horizontal distance 124(FIG. 3A), the second horizontal distance 128 (FIG. 3A), and the firstvertical distance 132 (FIG. 3B), respectively. Most preferably, thefirst horizontal distance 124′, the second horizontal distance 128′, andthe first vertical distance 132′ may be between about 90% and about 95%of the first horizontal distance 124 (FIG. 3A), the second horizontaldistance 128 (FIG. 3A), and the first vertical distance 132 (FIG. 3B),respectively.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention asset forth in the appended claims. The specification and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense.

1. A golf club head comprising: a cup-face portion comprising a centerapex and a top edge, the cup-face portion comprising a metallicmaterial; a body portion comprising a metallic material and including asole portion and an intermediate portion; a hosel having a hoselcenterline, wherein the club head is oriented relative to an imaginaryhorizontal ground plane so that the hosel centerline is in a firstimaginary vertical plane generally parallel to the top edge of thecup-face portion, the hosel centerline oriented at an angle of 60°relative to the imaginary horizontal ground plane; a peripheralattachment zone between the cup-face portion and the body portion, theperipheral attachment zone comprising a perimetric length, and at leasttwo discrete welds comprising between about 1% and about 40% of theperimetric length; a peripheral edge forming a perimetric boundary ofthe golf club head in a top plan view; and a second imaginary verticalplane substantially perpendicular to the strike face, the secondimaginary vertical plane containing a path that originates at the topedge of the cup-face portion and terminates at the peripheral edge ofthe golf club head, the path characterized by an intersection betweenthe second imaginary vertical plane and the top portion of the clubhead, the path comprising at least two articulation points.
 2. The golfclub head of claim 1, further comprising: imaginary vertical segmentsbetween the path and the imaginary horizontal ground plane, wherein theimaginary vertical segments are evenly spaced along the path, in itsentirety, in horizontal increments of 1 cm, the imaginary verticalsegments averaging between about 35 mm and about 45 mm in length.
 3. Thegolf club head of claim 2, wherein the imaginary vertical segmentsaverage between about 36 mm and about 41 mm in length.
 4. The golf clubhead of claim 2, wherein the imaginary vertical segments average betweenabout 37 mm and about 40 mm in length.
 5. The golf club head of claim 1,further comprising: a total mass between about 150 g and about 250 g;and at least one non-metallic portion comprising at least about 8% ofthe total mass.
 6. The golf club head of claim 1, further comprising aprimary high-low moment of inertial of at least about 2500 g·cm².
 7. Thegolf club head of claim 6, further comprising a primary heel-toe momentof inertia of at least about 3500 g·cm².
 8. The golf club head of claim7, wherein the primary heel-toe moment of inertia is at least about 4000g·cm².
 9. The golf club head of claim 1, further comprising a firstresonant frequency of vibration between about 2000 Hz and about 7500 Hz.10. The golf club head of claim 1, further comprising a first resonantfrequency of vibration between about 2600 Hz and about 6000 Hz.
 11. Thegolf club head of claim 1, further comprising a first resonant frequencyof vibration between about 3200 Hz and about 5000 Hz.
 12. The golf clubhead of claim 1, wherein the strike surface includes a sweet spot and aface center, the sweet spot being substantially coincident with the facecenter.
 13. The golf club head of claim 1, further comprising an overalllength greater than 75 mm.
 14. The golf club head of claim 1, furthercomprising an overall width greater than 75 mm.
 15. The golf club headof claim 1, further comprising a face height between about 45 mm andabout 58 mm.
 16. The golf club head of claim 1, wherein the at least twodiscrete welds comprise between about 1% and about 20% of the perimetriclength.
 17. The golf club head of claim 1, wherein the at least twodiscrete welds comprise between about 1% and about 30% of the perimetriclength.
 18. The golf club head of claim 1, wherein the cup-face portionand the intermediate portion are composed of different materials.